The
Trickster was played by actor Mark Hamill in the 1990s Flash series.
He will reprise the role in the new Flash series as an older imprisoned Trickster who must track down a new upstart Trickster. The younger
Trickster (Axel Walker version) will be played by Devon Graye. This episode will appear on March 31st.

Synopsis:MARK
HAMILL (“STAR WARS”) REPRISES HIS ROLE AS THE TRICKSTER — A copycat
killer who goes by the name “The Trickster” (guest star Devon Graye)
starts setting off bombs in Central City. In order to stop the villain,
Barry (Grant Gustin) and Joe (Jesse L. Martin) meet with the original
Trickster, a criminal mastermind named James Jesse (guest star Mark
Hamill), who has been imprisoned for 20 years. Things quickly go from
bad to worse when the Tricksters unite and take Henry (John Wesley
Shipp) prisoner. Meanwhile, Iris (Candice Patton) asks Eddie (Rick
Cosnett) for help with a case, and flashbacks show how Harrison Wells
(Tom Cavanagh) came up with the idea for the particle accelerator. Ralph
Hemecker directed the episode written by Andrew Kreisberg.